Overview
The LM2577T-ADJ/LB03-NS is a high-performance, step-up switching regulator IC produced by National Semiconductor. This component is part of the SIMPLE SWITCHER family and is designed to provide all the necessary power and control functions for various DC-DC converter applications. It features a wide input voltage range of 3.5V to 40V and can deliver an adjustable output voltage. The LM2577T-ADJ/LB03-NS is available in a TO-220 package, making it suitable for a variety of power supply designs.
Key Specifications
| Parameter | Conditions | Typical | Limit |
|---|---|---|---|
| Supply Voltage (VIN) | 3.5V to 40V | - | - |
| Output Switch Voltage (VSWITCH) | 0V to 60V | - | - |
| Output Switch Current (ISWITCH) | - | - | ≤3.0A |
| Junction Temperature Range | - | - | −40˚C ≤ TJ ≤ +125˚C |
| Output Voltage (VOUT) | VIN = 5V to 10V, ILOAD = 100 mA to 800 mA | 12.0V (for LM2577-12) | 11.60/11.40 V(min), 12.40/12.60 V(max) |
| Line Regulation | VIN = 3.5V to 10V, ILOAD = 300 mA | 20 mV | 50/100 mV(max) |
| Load Regulation | VIN = 5V, ILOAD = 100 mA to 800 mA | 20 mV | 50/100 mV(max) |
| Efficiency | VIN = 5V, ILOAD = 800 mA | 80% | - |
| Oscillator Frequency | - | 52 kHz | 48/42 kHz(min), 56/62 kHz(max) |
| Maximum Duty Cycle | VCOMP = 1.5V | 95% | 93/90 %(min) |
| Switch Saturation Voltage | ISWITCH = 2.0A, VCOMP = 2.0V | 0.5 V | 0.7/0.9 V(max) |
| Current Limit | - | - | 3.7/3.0 A(min), 5.3/6.0 A(max) |
Key Features
- Wide Input Voltage Range: 3.5V to 40V, making it versatile for various power supply applications.
- Adjustable Output Voltage: The LM2577T-ADJ/LB03-NS allows for adjustable output voltage, providing flexibility in design.
- High Output Switch Current: Capable of handling up to 3.0A output switch current.
- Internal Oscillator: Features a 52 kHz internal oscillator, simplifying the design process.
- Soft-Start Function: Reduces in-rush current during start-up, enhancing reliability and reducing stress on the system.
- Protection Features: Includes current limit, under-voltage lockout, and thermal shutdown to ensure safe operation.
- High Efficiency: Achieves an efficiency of up to 80%, making it suitable for power-conscious designs.
Applications
- Simple Boost Regulators: Ideal for step-up voltage conversion in various electronic devices.
- Flyback and Forward Regulators: Can be used in flyback and forward converter configurations.
- Multiple-Output Regulators: Suitable for designs requiring multiple output voltages.
- Industrial and Consumer Electronics: Used in power supplies for industrial equipment, consumer electronics, and other applications requiring reliable DC-DC conversion.
Q & A
- What is the input voltage range of the LM2577T-ADJ/LB03-NS?
The input voltage range is 3.5V to 40V.
- What is the maximum output switch current of the LM2577T-ADJ/LB03-NS?
The maximum output switch current is 3.0A.
- What is the typical oscillator frequency of the LM2577T-ADJ/LB03-NS?
The typical oscillator frequency is 52 kHz.
- Does the LM2577T-ADJ/LB03-NS have built-in protection features?
Yes, it includes current limit, under-voltage lockout, and thermal shutdown.
- What is the maximum junction temperature for the LM2577T-ADJ/LB03-NS?
The maximum junction temperature is +125˚C.
- What package types are available for the LM2577T-ADJ/LB03-NS?
It is available in a TO-220 package.
- Can the LM2577T-ADJ/LB03-NS be used in flyback and forward converter configurations?
Yes, it can be used in both flyback and forward converter configurations.
- What is the efficiency of the LM2577T-ADJ/LB03-NS at full load?
The efficiency can be up to 80% at full load.
- Does the LM2577T-ADJ/LB03-NS have a soft-start function?
Yes, it includes a soft-start function to reduce in-rush current during start-up.
- What is the storage temperature range for the LM2577T-ADJ/LB03-NS?
The storage temperature range is −65˚C to +150˚C.
